Spinocerebellar ataxia type 8 (SCA8) (Spinocerebellar ataxia type 8) - Gen ATXN8OS.

Spinocerebellar ataxia is a clinically and genetically heterogeneous group of disorders of the cerebellum group in which affected individuals show a progressive deterioration of locomotor coordination, dysarthria, and eye movements uncoordinated, because cerebellar degeneration with variable involvement of the brainstem and spinal cord.

Spinocerebellar ataxia type 8 (SCA8) is a neurodegenerative disease caused by a trinucleotide repeat expansion CTG / CAG in ATXN8OS gene, located on the long arm of chromosome 13 (13q21). This gene is an antisense gene transcription for KLHL1. Expansion probably interferes with the normal function of this antisense transcript. A bidirectional transcription in the chromosome locus 13q21 SCA8 in that implies both a CTG trinucleotide repeat expanded in ATXN8OS gene and a complementary ATXN8 CAG repeat in the gene. These variations result in expression of a mRNA transcript CUG protein expansion and polyglutamine, respectively, suggesting a gain of toxic function both protein and RNA levels. Often this molecular defect called repeat expansion of "CTG CAG *" referring to complementary base pairs of the genes ATXN8 ATXN8OS and reading the 5'to 3'.

This disease is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient for the disease to be expressed.  

Tests in IVAMI: in IVAMI perform detection of mutations associated with spinocerebellar ataxia type 8 (SCA8), by complete PCR amplification of exons ATXN8OS gene, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).